The field of art of the invention is bored hole plug devices.
Substrates such as walls of buildings, sidewalks, parking lots, patios, pool decks, and other structures ordinarily prevent access for inspection of the condition of termite baiting materials, plumbing and waterlines, wiring, mechanical devices such as pumps, and is other components below the surface of the substrates. Such subsurface components can be accessed by boring a hole into the substrate. The bore hole can be sealed with a removable cover to allow reaccess to the bore hole and the components therein.
The present invention relates to improvements over removable bore hole plug deices, including particularly the tamper resistant bait cover and bait access system disclosed in U.S. Pat. 5,927,000 (Edgar S. Bordes). Bordes shows a design of a bore hole cover assembly that can be placed in a hole that is bored through the substrate. The bore hole cover assembly described by Bordes prior art is composed of a top plate, a bottom plate, and a rubber gasket affixed together using a bolt and nut welded to the bottom plate. In actual practice, Bordes design is manufactured using a metal top plate, a metal bottom plate, a metal bolt, a metal nut welded to the bottom plate, and a rubber gasket. The metal top and bottom plates are modified aluminum plumbers plugs. These bottom plate nut assemblies have significantly corroded when hole covers made according to Bordes prior art and manufacturing design have been installed in humid and wet locations. This corrosion causes the nut assembly to fail and therewith the entire Bordes hole cover assembly to fail. Because the nut is welded to the bottom plate, the entire bottom plate must be replaced when this failure occurs. Corrosion is a particular problem in this field of art because termites and other such destructive insects significantly inhabit geographic areas of high humidity and wetness. Top plates and bottom plates of the Bordes design can not be made of inexpensive non-corrosive plastic materials.
Other deficiencies of the prior art of Bordes and Bordes manufacturing design are the failure of Bordes to: a) specify a means of seating the compression gasket in place to achieve firm and uniform compression against the sides of the hole bored in the substrates; b) provide for an at-rest curved top to compensate for the downward deflection of the top, the lack of which causes water to collect on the top and internally, accelerating corrosion; and (c) to provide for resiliency in Bordes top plate to address the possible permanent deformation of the top plate when the top plate is struck or depressed with a hammer, heavy equipment, etc., said deformation causing Bordes apparatus to become less tamper resistant or more difficult to remove for inspection purposes.
Additionally, hole cover top plates manufactured in accordance with Bordes prior art and manufacturing design and of the designs of others are not colored to closely match the surface of the substrate into which they are installed. Therefore, the current hole covers are visually apparent and attract vandals. In part as a result of the higher visibility, a number of hole covers have been damaged, removed, or stolen, exposing the bait materials in termite bait traps and giving unwanted access to children and the general public to termite treatment chemicals and other subsurface components.
Several models of bore hole covers for insecttreatment and/or inspection have been made in addition to that shown in Bordes prior art and manufacturing design. See U.S. Pat. No. 2,155,491 (Jacobs); U.S. Pat. No. 2,245,887 (Wikander); U.S. Pat. No. 3,667,640 (Morrow); U.S. Pat. No. 3,910,191 (Williams). To the best of the inventor""s knowledge, all of these models and that shown in Bordes prior art and manufacturing design are composed of multiple piece bodies that utilize a combination metal with welded parts and/or a rubber compression ring gasket or do not employ all or the combination of the design particulars of the inventor.
The inventor has designed an improved bore hole cover apparatus that solves the foregoing deficiencies and problems of the prior art, and that can be economically manufactured using conventional molding techniques.
It is an object of the invention to provide a non-corrosive bore hole cover assembly.
It is another object of the invention to provide a non-corrosive bore hole cover assembly in which the top plate, bottom plate, and ring gasket are designed to be manufactured of inexpensive plastics.
It is another object of the invention to provide a non-corrosive bore hole cover assembly in which the top plate is manufactured from a material that can be color matched to the bored substrate.
It is another object of the invention to provide a non-corrosive bore hole cover assembly in which the bottom plate has a replaceable threaded insert which can be replaced should failure occur.
It is another object of the invention to provide a non-corrosive bore hole cover assembly in which the top plate and the bottom plate have circular locating rings that maintain the alignment of the compression ring gasket.
It is yet another object of the invention to provide a non-corrosive bore hole cover assembly in which the bottom plate has an internal bolt locating ring to assist in the assembler in starting the connecting bolt.
These and other objects and advantages of the invention shall become apparent from the following general and preferred description of the invention.
A non-corrosive bore hole cover apparatus for plugging a hole bored in a substrate is provided comprising, generally, a top plate molded from a non-metallic material, a bottom plate molded from a non-metallic material, a compressible ring gasket sandwiched between the top and bottom plates, and a bolt passing through the top plate, gasket, and bottom plate, the bolt being positioned and configured to selectively draw the top and bottom plates together to compress the ring gasket. The top plate has a hole therethrough, and a bottom side of the top plate has an annular gasket locating ridge formed thereon. The bottom plate has a threaded hole therein, and a top side of the bottom plate has an annular gasket locating ridge formed thereon. The gasket locating ridges are of substantially equal outer diameter. The compressible ring gasket has an elongated wall and an inner diameter sized to tightly encircle the outer diameter of the gasket locating ridges. The compressible ring gasket is sandwiched between the top plate and the bottom plate such that the gasket locating ridges are inserted in either end of the compressible ring gasket. The threaded bolt passes through the top plate hole such that a head of the bolt is retained against a top side of the top plate and a lower or tail end of the bolt is threaded through the hole of the bottom plate. The bolt may be selectively rotated into the threaded hole to draw the top and bottom plate toward one another to thereby compress and circumferentially expand the ring gasket. The gasket locating ridges maintain alignment of the compressible ring gasket and the top and bottom plates during compression to thereby achieve substantially uniform compression against the bore hole.
The top and bottom plates are preferably molded from a glass reinforced polymer. The top side of the top plate preferably has a convex configuration so as to compensate for downward deflection of the top plate during compression of the compressible gasket ring and to reduce pooling of water on the top plate. The bottom side of the top plate preferably has a plurality of reinforcement ribs formed thereon, the reinforcement ribs radiating outward about the top plate hole, the rib members providing reinforcement for the top plate. A top surface of the top plate is preferably recessed about the top plate hole such that a head of the bolt is substantially flush with the top surface of the top plate to thereby reduce water pooling on the top plate. The top side of the bottom plate preferably has a tapered bolt locating ridge formed about the threaded hole.
The compressible ring gasket preferably has a plurality of ribs formed on an inner side of the elongated wall, the gasket ribs being positioned longitudinally about the inner side of the elongated wall to thereby reinforce the ring gasket during compression. The gasket ribs permit the compressible ring gasket to be of thin-walled construction and of reduced weight. The compressible ring gasket is molded from a non-rubber thermal plastic elastomer.
The bottom plate preferably has a plurality of rib members formed thereon, the bottom plate rib members radiating outward about the threaded hole, the bottom plate rib members providing reinforcement for the bottom plate. The rib members are preferably positioned on a bottom side of the bottom plate.
The threads of the bottom plate hole may be molded into the bottom plate. In a preferred embodiment, the threads of the bottom plate hole are provided by a non-corrosive threaded winged t-nut disposed in the hole, the wings of the t-nut configured and positioned to engage the bottom plate rib members so as to assist in maintaining the t-nut in fixed non-rotational relation to the bottom plate. A retaining means, such as a locking nut, may be secured to a tail end of the threaded bolt for preventing the bottom plate from separating from the apparatus during removal of the apparatus from the bore hole.
The top plate is preferably of a color selected to substantially match a color of a surface of the substrate. The bottom plate and gasket may also be selected to match the color of the surface of the substrate. The components of the apparatus are preferably constructed from materials that can be re-ground and recycled to manufacture duplicate replacement parts.
The apparatus is used by inserting the bore hole cover in the opening of the bore hole such that the top plate rests against a surface of the substrate, and then rotating the bolt to thereby circumferentially compress the compressible ring gasket against the bore hole and thereby seal the bore hole. A termite bait material may be inserted in the bore hole prior to closing the bore hole with the bore hole cover. The color of the bore hole cover may be selected such that the color of the bore hole cover substantially matches a color of the surface of the substrate. When the threads of the threaded hole have become worn or unuseable through overuse or over torquing, the threads can be replaced by removing the bore hole cover from the bore hole, removing the bottom plate from the apparatus, removing the t-nut from the bottom plate hole, and inserting a new t-nut in the bottom plate hole.